My crimson Dragon
by Nightfury262
Summary: Rias always wanted a familiar that matched her childish personality. On one fateful day she found one.
1. Chapter 1

**In the Underworld, Familiar forest**

From a distance you would believe that it was an ordinary forest, with ordinary trees and ordinary animals. If you were to get closer however you would notice that all the living organisms aren't what you'd call natural. In the centre of a forest there is an immense mountain with a large cave at the base, where two glowing golden eyes can be seen glaring out over the expanse of woodland that this mighty creature calls home.

 **"Soon"** it thought **"Soon I will meet a devil worthy to be my master and I their familiar"**

After which it let out a tremendous roar that shook the entirety of the forest. Then closed it's eyes to wait.

 **Three days later**

"I just know I'm going to find it" shouted the young girl that sat on the head of a red scaled reptile like creature.

"Settle down Rias, choosing your familiar is very important to becoming a high class devil" said the crimson haired satan. This happened to be Sirzechs lucifer the current head of the devils and the king of the underworld. with him he has his younger sister Rias, his mother and father, Lady and Lord Gremory and his queen Grayfia lucifuge, the silver haired queen of annihilation.

With them was also the familiar master, Zatuji, who carried with him a book of all the possible familiars.

"So Rias what were you thinking of your familiar being like?" asked her brother with a gentle smile on his face.

"I want one that's very powerful and that can scare Riser-baka," It was common knowledge throughout the underworld of the young heiress' displeasure towards her future fiancé. "I also want it to be the same colour as my hair," she exclaimed whilst showing the others a lock of her crimson coloured hair.

"I am afraid there is nothing in this book that matches your requirements my dear," said Zatuji.

The others looked pityingly towards the now pouting girl.

"But he said there is a creature in this forest that matches your description, but I'm afraid you can't make it your familiar."

"Why not?" she sulked now once again pouting.

The others were also very confused as Zatuji had been known to support anyone's decision on familiar.

"That's because it is the largest dragon I have ever seen," he explained, "he arrived in the underworld 60 years ago and would hunt down any strong opponents it could find. Others have tried to make him their familiar but all were sent away by a large stream of fire even Riser Phenex tried and failed so ended up with a fire eagle.

This however only made Rias more excited at the prospect of having something that Riser couldn't have. "Now I am definitely going to get it so I can finally be rid of that baka," however whatever she was going to say was cut off as she was plucked off her standing position on the lizard and was carried off by a large eagle.

"Rias-chan!" exclaimed the satan in panic, "We have to catch her he shouted to the others while spreading his wings.

"Yes Sirzechs-sama came the instant reply.

 **With Rias**

Rias kept screaming hoping that someone would come an save her. As they got closer to the mountain she noticed a nest and screeching noises coming from within. To her horror she realised that she was going to be eaten alive. This sudden realisation caused her to start crying harder.

Suddenly there was a tremendous roar which caused the eagle to start panicking. Rias turned around and gasped at what she saw. Barrelling towards them was an enormous dragon. It was covered in glinting red scales with a tan under-belly, it had a triangular head with a large horn at the end of it's snout.

It let out another ear splitting roar and covered the distance between them in a matter of seconds. It then lunged at the eagle grapping it in it's large paw.

The bird tried to fight back but the dragon just squeezed it's paw causing the bird to cry out in pain while also releasing the young girl in it's talons.

Rias screamed out in shock as she fell, whilst on the ground the Satan had opened his wings ready to catch her. But as they did this the dragon dived down and caught young Rias in his paw while gently lowering itself to the ground. All the while thinking **"I have finally found it, I have found the one that will free me from this curse of perpetual loneliness,"** Back on the ground Rias launched herself into her brother's arms, who after noticing the large gashes on her arms quickly activated a healing spell.

After Rias had calmed down he turned to the dragon who during all of this had quickly shrunk down to an average sized dragon. The others who had just caught up gasped in shock after witnessing this.

Sirzechs turned towards the dragon and said "Thank you for saving her," The dragon nods it's head in understanding.

"This is incredible a large dragon showing kindness to a young devil, this has never been seen before," exclaimed Zatuji

"Quickly Rias" Sirzechs whispered in her ear "try and make him your familiar,"

"Hey Mr dragon would you like to be my familiar" she questioned. The dragon raised it's head and looked to be in consideration before bending down and blew hot air at Rias knocking her onto her backside. "Hey!" she whined "Do you want to be my familiar or not?"

The dragon then bowed it's head to her as a sign of acceptance. Rias giggled in glee.

"I Rias Gremory here by summon you to be my familiar to help me your master in what ever I may need." Then a giant crimson magic circle appeared underneath the dragon with it in the centre.

"Grayfia darling could you organise a party for when we get back please?" said Venelana

"Yes of course"

"But why mother?" asked Rias

"Because my dear when news gets out that you have a dragon as a familiar all the newspaper will go mad in trying to find out how you managed to get a dragon to be your familiar."  
After turning back to the dragon, Rias exclaimed, "I'm going to call you Natsu"  
The others sweat dropped at this as it was such a childish name for such a powerful dragon, but to a 10 year old Rias she didn't care as she had finally found her familiar, one that would soon strike fear into the hearts of anyone who would be stupid enough to go against them.  
'Natsu' then bent down in a way that showed he wanted her to get on.  
"Oh no you don't Rias," her mother shouted with panic and worry setting in to her voice while lunging forward to stop her.  
Rias replied by sticking her tongue out at her as she dodged out of the way of her mother's hand.

Natsu as Rias got closer angled his leg to allow her to climb on easier. She jumped on and positioned herself in a comfortable spot and signalled to Natsu to take off. Then he spread his massive wingspan and took off, blowing away the surrounding trees. The others watching from the ground could only smile as they listened to Rias' giggles of joy as they tried to keep up with the dragon.

Rias then lied on her back and stroked Natsu's glistening crimson scales as they soared through the sky and smiled. Unknown to everyone else, Natsu as well was smiling.

 **At the Gremory mansion.**

When everyone had arrived, Natsu slowed down to come in for a landing in the Gremory's large garden. As he landed the earth shook a little then he lowered himself to allow Rias to get off.

When everyone got ready to go inside Sirzechs told Natsu, "I'm afraid you can't come in as you are too big to fit inside."Rias turned back around and flung her arms around Natsu's head and whispered, "Good night Natsu, I will see you in the morning." Once they had all left Natsu shrunk down and lowered himself to the ground, resting his head on his paws he shut his eyes and went to sleep.


	2. Chapter 2

**The next morning.**

"Hi Natsu," said Rias.

The dragon stirred and opened one of it's eyes to look at her.

"I'm afraid I have to leave and go to School today," But after seeing the dragon's disheartened look, quickly replied "But don't worry because this is the underworld having your familiar with you is compulsory, which means that you can come with me,"

After hearing this it was easy to see how quickly Natsu had cheered up as his tail was swaying side to side. During their conversation Sirzechs and the others had walked over. Then Sirzechs said "Please Natsu can you look after her?"

Natsu just made a sign to show his agreement. "Very well then, you are free to go, be good for Natsu Rias," said Venelana.

Rias just nodded her head.

"Bye mom, dad, brother and Grayfia," she screamed out as she jumped onto Natsu's back as he prepared to take off.

They shouted back to her and waved as Natsu steadily rose into the sky.

"Let's go Natsu, school is west from her."

As they got closer to the school Rias thought of a plan to prank everyone at school. She leaned down and whispered her plan into Natsu's ear.

Natsu then quickly landed close to the school and Rias quickly got off to explain her plan better. "When I get into school I want you to listen in on where I am, then I want you to roar and then land outside and look into the classroom I am in."

Natsu gave a rumble in agreement. Then Rias left to school.

 **At school**

When everyone was inside the school the headteacher said "Now, now children before we start the day I would like to warn you that there has been a possible dragon sighting nearby, so I would like you all to take extra care while being outside this week. All of you are dismissed and can go to your classrooms." Then everyone got up to leave Rias quickly talked to Natsu via telepathy while everyone else was discussing about the dragon.

Everyone was sat in the classroom while showing off their familiars to the others. When it came to Rias's turn before she could open her mouth Riser shouted out, "I bet she has a really lame one if she even has one at all." Rias glared at him and before she could respond there came a terrifying **ROAR** and there was a loud thud outside.

Opening the doors all of the devils gasped in shock as standing before them was a ginormous black and blue dragon.

"That's Acnologia run for it!" The dragon glared down at them and opened its mouth and gathered energy inside its mouth ready to blast them into oblivion. All of the devils started crying and screaming when suddenly another dragon this time red lunged at the other dragon and sent it flying into the nearby forest and quickly flew after it, breathing fire at the dragon of the apocalypse. The ball of fire hit the dragon causing a nuclear explosion dust cloud, which sent a massive shock wave flying in all directions, knocking everything in the nearby vicinity onto the ground. However it just missed the gathering devils and the school.

Once the dust had settled it could be seen that nothing remained of the once infamous dragon, not even ashes. The red dragon flew down towards them and landed in front of the devils and roared into the sky in triumph. All the devils gazed up at it in shock at seeing it one shot the most powerful dragon in existence.All the young devils that didn't have a familiar all ran up to asking it whether it would be their familiar. However it just ignored them to focus on Rias to the shock and confusion to the others.Then it was Rias who said something that blew everyone away, "Everyone I would like you to meet my familiar the new most powerful dragon in the underworld." Everyone's jaws dropped in sync. After Riser had recovered he started spluttering angrily, "That's the dragon that I tried with and it chose you over me?!" Then without warning the dragon got up on its hind legs and roared right in Riser's face. Riser screamed and secretly wet himself. Everyone started laughing at how one of the sons of a high class devil was screaming like a little girl. Even Natsu started laughing in his own draconic way. Riser red from embarrassment and anger turned around and stormed off.After calming down everyone went back inside and continued with the day's lessons.

 **After School**

When Rias got home she was greeted by her overly concerned parents and brother, "We heard what happened at school today, thank Maou you're all right."

"I'm fine" replied Rias in her normal cheery voice, "Natsu protected me, and he killed Acnologia the apocalypse dragon in one shot, it was so awesome," she said.

"It was a good thing that she found him then otherwise I don't know what would have happened to us if something happened to you." Said lord Gremory in a relieved tone. Walking up to the dragon he said "Thank you Natsu, you have our gratitude for you saving Rias." Lord Gremory said.

Natsu just nodded as he closed his eyes in thought.

"Alright Rias, you can go and play with your familiar but make sure to stay within the grounds as we don't want to have a repeat of what has happened now do we?" Lady Gremory said.

"Of course Mother, I'll stay with Natsu at all times, hey Natsu do you want to play with me?" She asked as she ran up to him looking up at his head for a response. Natsu lowered his large head down to her and gave her his best attempt at a smile. Rias' mood immediately picked up at the sign of his agreement. So that's what they'd do everyday after Rias got back from school.

 **Five years later:**

"I'm sorry Natsu, but I have to go to school in the human world and you can't come with me as you're too large and the sight of a dragon would cause a mass panic and then you'd be hunted and people would try to kill you, then you'd fight back and there would be a massive death toll, then you'd be classed as a stray and would have hundreds of devils trying to kill you to increase their fame. If you died I wouldn't forgive you for leaving me!" She exclaimed with tears in her eyes. Natsu wrapped his tail around her waist and sat her down on his snout so he could look at her, looking softly into her eyes and gave a comforting humming sound so to soothe her as she hugged his snout, with tears flowing down her cheeks. After several minutes of being in that position she broke off from the hug and climbed down and said, "It's time for me to go, don't worry I'll come back for the weekends and the holidays and Grayfia can look after you while I'm gone." After a few minutes of convincing Natsu finally relented and lay down on his front legs and just watched as Rias left.

10 minutes after Rias left to go to the human world, Grayfia walked up to the sulking dragon and patted the side of his face in comfort. They both stayed like that for a few minutes before Grayfia spoke to him, as she said, "Don't worry too much she'll be fine, she'll have friends to look after her," then after slight hesitation she again said "You're a very strange dragon you know, you have a lot of human like qualities even though you're a multi tonne fire breathing flying reptile." She said in amusement at watching the dragon sulk as it's tail twitched impatiently.


End file.
